/*
 * Date Format 1.2.3
 * (c) 2007-2009 Steven Levithan <stevenlevithan.com>
 * MIT license
 *
 * Includes enhancements by Scott Trenda <scott.trenda.net>
 * and Kris Kowal <cixar.com/~kris.kowal/>
 *
 * Accepts a date, a mask, or a date and a mask.
 * Returns a formatted version of the given date.
 * The date defaults to the current date/time.
 * The mask defaults to dateFormat.masks.default.
 */

(function(global) {
  'use strict'

  var dateFormat = (function() {
    var token = /d{1,4}|m{1,4}|yy(?:yy)?|([HhMsTt])\1?|[LloSZWN]|"[^"]*"|'[^']*'/g
    var timezone = /\b(?:[PMCEA][SDP]T|(?:Pacific|Mountain|Central|Eastern|Atlantic) (?:Standard|Daylight|Prevailing) Time|(?:GMT|UTC)(?:[-+]\d{4})?)\b/g
    var timezoneClip = /[^-+\dA-Z]/g

    // Regexes and supporting functions are cached through closure
    return function (date, mask, utc, gmt) {
      // You can't provide utc if you skip other args (use the 'UTC:' mask prefix)
      if (arguments.length === 1 && kindOf(date) === 'string' && !/\d/.test(date)) {
        mask = date
        date = undefined
      }

      date = date || new Date()

      if (!(date instanceof Date)) {
        date = new Date(date)
      }

      if (isNaN(date)) {
        throw TypeError('Invalid date')
      }

      mask = String(dateFormat.masks[mask] || mask || dateFormat.masks['default'])

      // Allow setting the utc/gmt argument via the mask
      var maskSlice = mask.slice(0, 4)
      if (maskSlice === 'UTC:' || maskSlice === 'GMT:') {
        mask = mask.slice(4)
        utc = true
        if (maskSlice === 'GMT:') {
          gmt = true
        }
      }

      var _ = utc ? 'getUTC' : 'get'
      var d = date[_ + 'Date']()
      var D = date[_ + 'Day']()
      var m = date[_ + 'Month']()
      var y = date[_ + 'FullYear']()
      var H = date[_ + 'Hours']()
      var M = date[_ + 'Minutes']()
      var s = date[_ + 'Seconds']()
      var L = date[_ + 'Milliseconds']()
      var o = utc ? 0 : date.getTimezoneOffset()
      var W = getWeek(date)
      var N = getDayOfWeek(date)
      var flags = {
        d: d,
        dd: pad(d),
        ddd: dateFormat.i18n.dayNames[D],
        dddd: dateFormat.i18n.dayNames[D + 7],
        m: m + 1,
        mm: pad(m + 1),
        mmm: dateFormat.i18n.monthNames[m],
        mmmm: dateFormat.i18n.monthNames[m + 12],
        yy: String(y).slice(2),
        yyyy: y,
        h: H % 12 || 12,
        hh: pad(H % 12 || 12),
        H: H,
        HH: pad(H),
        M: M,
        MM: pad(M),
        s: s,
        ss: pad(s),
        l: pad(L, 3),
        L: pad(Math.round(L / 10)),
        t: H < 12 ? dateFormat.i18n.timeNames[0] : dateFormat.i18n.timeNames[1],
        tt: H < 12 ? dateFormat.i18n.timeNames[2] : dateFormat.i18n.timeNames[3],
        T: H < 12 ? dateFormat.i18n.timeNames[4] : dateFormat.i18n.timeNames[5],
        TT: H < 12 ? dateFormat.i18n.timeNames[6] : dateFormat.i18n.timeNames[7],
        Z: gmt ? 'GMT' : utc ? 'UTC' : (String(date).match(timezone) || ['']).pop().replace(timezoneClip, ''),
        o: (o > 0 ? '-' : '+') + pad(Math.floor(Math.abs(o) / 60) * 100 + Math.abs(o) % 60, 4),
        S: ['th', 'st', 'nd', 'rd'][d % 10 > 3 ? 0 : (d % 100 - d % 10 != 10) * d % 10],
        W: W,
        N: N
      }

      return mask.replace(token, function (match) {
        if (match in flags) {
          return flags[match]
        }
        return match.slice(1, match.length - 1)
      })
    }
  })()

  dateFormat.masks = {
    'default': 'ddd mmm dd yyyy HH:MM:ss',
    'shortDate': 'm/d/yy',
    'mediumDate': 'mmm d, yyyy',
    'longDate': 'mmmm d, yyyy',
    'fullDate': 'dddd, mmmm d, yyyy',
    'shortTime': 'h:MM TT',
    'mediumTime': 'h:MM:ss TT',
    'longTime': 'h:MM:ss TT Z',
    'isoDate': 'yyyy-mm-dd',
    'isoTime': 'HH:MM:ss',
    'isoDateTime': 'yyyy-mm-dd\'T\'HH:MM:sso',
    'isoUtcDateTime': 'UTC:yyyy-mm-dd\'T\'HH:MM:ss\'Z\'',
    'expiresHeaderFormat': 'ddd, dd mmm yyyy HH:MM:ss Z'
  }

  // Internationalization strings
  dateFormat.i18n = {
    dayNames: [
      'Sun', 'Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat',
      'Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday'
    ],
    monthNames: [
      'Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec',
      'January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December'
    ],
    timeNames: [
      'a', 'p', 'am', 'pm', 'A', 'P', 'AM', 'PM'
    ]
  }

  function pad(val, len) {
    val = String(val)
    len = len || 2
    while (val.length < len) {
      val = '0' + val
    }
    return val
  }

  /**
 * Get the ISO 8601 week number
 * Based on comments from
 * http://techblog.procurios.nl/k/n618/news/view/33796/14863/Calculate-ISO-8601-week-and-year-in-javascript.html
 *
 * @param  {Object} `date`
 * @return {Number}
 */
  function getWeek(date) {
  // Remove time components of date
    var targetThursday = new Date(date.getFullYear(), date.getMonth(), date.getDate())

    // Change date to Thursday same week
    targetThursday.setDate(targetThursday.getDate() - ((targetThursday.getDay() + 6) % 7) + 3)

    // Take January 4th as it is always in week 1 (see ISO 8601)
    var firstThursday = new Date(targetThursday.getFullYear(), 0, 4)

    // Change date to Thursday same week
    firstThursday.setDate(firstThursday.getDate() - ((firstThursday.getDay() + 6) % 7) + 3)

    // Check if daylight-saving-time-switch occurred and correct for it
    var ds = targetThursday.getTimezoneOffset() - firstThursday.getTimezoneOffset()
    targetThursday.setHours(targetThursday.getHours() - ds)

    // Number of weeks between target Thursday and first Thursday
    var weekDiff = (targetThursday - firstThursday) / (86400000 * 7)
    return 1 + Math.floor(weekDiff)
  }

  /**
 * Get ISO-8601 numeric representation of the day of the week
 * 1 (for Monday) through 7 (for Sunday)
 *
 * @param  {Object} `date`
 * @return {Number}
 */
  function getDayOfWeek(date) {
    var dow = date.getDay()
    if (dow === 0) {
      dow = 7
    }
    return dow
  }

  /**
 * kind-of shortcut
 * @param  {*} val
 * @return {String}
 */
  function kindOf(val) {
    if (val === null) {
      return 'null'
    }

    if (val === undefined) {
      return 'undefined'
    }

    if (typeof val !== 'object') {
      return typeof val
    }

    if (Array.isArray(val)) {
      return 'array'
    }

    return {}.toString.call(val)
      .slice(8, -1).toLowerCase()
  };

  if (typeof define === 'function' && define.amd) {
    define(function () {
      return dateFormat
    })
  } else if (typeof exports === 'object') {
    module.exports = dateFormat
  } else {
    global.dateFormat = dateFormat
  }
})(window.$ui)
